Skip to content

Commit 3849e91

Browse files
Aravind GopalakrishnanKAGA-KOKO
authored andcommitted
x86/AMD: Fix last level cache topology for AMD Fam17h systems
On AMD Fam17h systems, the last level cache is not resident in the northbridge. Therefore, we cannot assign cpu_llc_id to the same value as Node ID as we have been doing until now. We should rather look at the ApicID bits of the core to provide us the last level cache ID info. Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Huang Rui <ray.huang@amd.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jacob Shin <jacob.w.shin@gmail.com> Link: http://lkml.kernel.org/r/1446582899-9378-1-git-send-email-Aravind.Gopalakrishnan@amd.com Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
1 parent 8c058b0 commit 3849e91

1 file changed

Lines changed: 13 additions & 0 deletions

File tree

arch/x86/kernel/cpu/amd.c

Lines changed: 13 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -352,6 +352,7 @@ static void amd_detect_cmp(struct cpuinfo_x86 *c)
352352
#ifdef CONFIG_SMP
353353
unsigned bits;
354354
int cpu = smp_processor_id();
355+
unsigned int socket_id, core_complex_id;
355356

356357
bits = c->x86_coreid_bits;
357358
/* Low order bits define the core id (index of core in socket) */
@@ -361,6 +362,18 @@ static void amd_detect_cmp(struct cpuinfo_x86 *c)
361362
/* use socket ID also for last level cache */
362363
per_cpu(cpu_llc_id, cpu) = c->phys_proc_id;
363364
amd_get_topology(c);
365+
366+
/*
367+
* Fix percpu cpu_llc_id here as LLC topology is different
368+
* for Fam17h systems.
369+
*/
370+
if (c->x86 != 0x17 || !cpuid_edx(0x80000006))
371+
return;
372+
373+
socket_id = (c->apicid >> bits) - 1;
374+
core_complex_id = (c->apicid & ((1 << bits) - 1)) >> 3;
375+
376+
per_cpu(cpu_llc_id, cpu) = (socket_id << 3) | core_complex_id;
364377
#endif
365378
}
366379

0 commit comments

Comments
 (0)